Question

D Incorrect Your answer is incorrect. Suppose that the time required to complete a 1040R tax form is normally distributed with a mean of 100 minutes and a standard deviation of 15 minutes. What proportion of 1040R tax forms will be completed in at most 81 minutes? Round your answer to at least four decimal places. E 0.8980 5 ?

Answer 1

Answer:

Given,

Mean = 100

Standard deviation = 15

P(X < 81) = P((x-u)/s < (81 - 100)/15)

= P(z < - 1.27)

= 0.1020423 [since from z table]

= 0.1020